Cornforth Consultants
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      • OTIA Cracked Bridge Geotechnical Baselines
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      • Tanana River Bridge Foundation, Tok, Alaska
      • Montana RHRS Implementation
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Tanana River Bridge Replacement

Tok, Alaska
The Alaska Department of Transportation and Public Facilities needed to construct a new Tanana River Bridge at Mile 1303 of the Alaska Highway. The existing through-truss steel bridge was 60 years old and had suffered damage during the magnitude 7.9 earthquake that occurred in 2002. In that event, the foundation liquefied enough that the bridge shifted several inches on its bearing plates, and needed to be repositioned.

Due to the a very short design schedule, Landslide Technology, a division of Cornforth Consultants, Inc. joined the DOT team to provide site seismic analysis' liquefaction assessment, stability analysis of both abutments and embankments, rock cut slope and foundation recommendations, and a constructability review.
​
​The replacement structure is 900 feet long and consists of six concrete girder spans supported on five large-diameter, drilled shafts in the river with smaller-diameter shafts at the east abutment and a pile foundation at the west abutment. In spite of the short timeframe, the design and construction documents were completed in time to preserve the project funding, which otherwise would have been in jeopardy.

Type 2 RHRS Slope on Highway 26
Old Tanana River Bridge, Tok, Alaska

​Services Provided:

  • Analysis of liquefaction damage at existing bridge foundation
  • Analysis of potential seismic liquefaction
  • Bridge abutment stability analysis
  • Bridge foundation recommendations
  • Rock cutslope design recommendations
  • Design of drilled shaft and pile foundations
  • Constructability review
  • Plans and specifications
  • Home
  • Services
    • Earth & Rockfill Dams
    • Reservoirs, Canals, and Levees
    • Spillway Safety Inspections
    • Landslides and Rockfall
    • Earthquake Engineering
    • Geologic Hazards
    • Geotechnical Site Characterization
    • Hydrogeology
    • Expert Witness
    • Concrete Dams and Locks
    • Geotechnical Instrumentation
    • Deep and Shallow Foundations
    • Geotechnical Manuals
  • Industries
    • Water Resources
    • Energy
    • Natural Resources
    • Industrial
    • Transportation
    • Ports and Airports
    • Expert Witness
  • Projects
    • Earth and Rockfill Dams >
      • Barney Reservoir
      • Frog Lake Reservoir
      • Iron Gate Dam Raise
      • McGuire Dam Raise
      • Bonneville Cofferdam
      • Bull Run No. 2 Seismic Stability Analysis
    • Levees and Canals >
      • Libby Dike Rehab.
      • St. Johns Dike Stabilization
      • Cowlitz River Levees
      • Swift Canal Failure
    • Earthquake Engineering >
      • Barney Dam Seismic Analysis
      • Fern Hill WTP Liquefacation Study
      • Bull Run No. 2 Seismic Stability Analysis
      • Mt. Tabor Seismic Stability Analysis
      • Port Westward Power Plant Seismic Design
    • Rock Slopes and Tunnels >
      • Libby Rockfall Mitigation
      • Sandy River Pipeline Tunnels
      • Ketchikan Third Avenue Extension
      • Sain Creek Water Supply Tunnel
      • Montana Rockfall Hazard Rating System
    • Foundations >
      • Port Westward Power Plant
      • Cascade Locks Casino
      • Air National Guard Hangar
      • Biglow Canyon Windfarm
      • Oakridge Water System Improvements
    • Concrete Dams and Locks >
      • John Day Lock & Dam
      • Marmot Dam Removal
      • The Dalles Dam
      • Willamette Falls Dam
      • Bonneville Dam
    • Transportation >
      • OTIA Cracked Bridge Geotechnical Baselines
      • Newburg Dundee Bypass Design DEIS
      • I-84 Sandy River Bridge Investigation
      • Tanana River Bridge Foundation, Tok, Alaska
      • Montana RHRS Implementation
      • Ketchikan Third Avenue Extension
    • Ports and Airports >
      • Navy CVN Drydock
      • Depoe Bay Seawall Distress
      • Willamette Falls Flow Control Structure
      • Air National Guard Hangar
    • Water and Wastewater >
      • Fern Hill Water Treatment Plant
      • Tualatin Valley North Transmission Line
      • Evaluation of 28 Water Storage Facilities
      • City of Sandy Water Treatment Plant
      • Mt. Tabor Reservoir No. 5 Cap Study
      • Oakridge Water System Improvements
  • Staff
  • Resources
  • Careers
    • Geotechnical Engineer
  • Contact Us